Joseph Verner Reed Jr., who was under secretary for four secretaries general of the United Nations and, as chief of protocol under President George Bush, presided over one of the more colorful diplomatic gaffes in recent history, died on Thursday in Greenwich, Conn. He was 78.

Fraser P. Seitel, a friend and former colleague at Chase Manhattan Bank, said the cause was a heart attack.

Mr. Reed began his long career at the United Nations in 1985, after four years as ambassador to Morocco under President Ronald Reagan. He began as United States representative to the organization’s Economic and Social Council, where he was responsible for African issues, and later held the rank of under secretary general serving Javier Pérez de Cuéllar, Boutros Boutros-Ghali, Kofi Annan and the current secretary general, Ban Ki-moon, who appointed him as special adviser in 2007.

His enthusiasm for the United Nations — his license plate read “USA-UN” — occasionally led to conflict with Reagan, who regarded the organization with a cold eye. At a United Nations lunch in September 1988, Mr. Reed warned Reagan that unless the United States paid its back dues, he ran the risk of being known as the president who closed the doors on the organization.

Two months later, when the State Department barred Yasir Arafat, the chairman of the Palestine Liberation Organization, from entering the United States to address the General Assembly, Mr. Reed sent a scolding letter to the president, saying that the move would cause “incalculable damage to the United States’ credibility in the world arena.”

Mr. Reed absented himself from the United Nations for two years when the first President Bush, whose parents had been close friends of his parents in Connecticut, appointed him chief of protocol in 1989.

He threw himself into the job, much of it involving the care and handling of resident diplomats and foreign heads of state visiting Washington. New ambassadors delighted at the flourish of trumpets, waving of flags and presidential one-on-one that now constituted the official greeting package.

“It used to be a 30-second in and out with just a quick handshake,” Mr. Reed told The New York Times in 1989. “Now it’s a warm welcome by the leader of the free world and the first lady of the land.”

Exuberance sometimes led him astray. He told an audience at Hofstra University in 1997, jokingly, that he had committed more gaffes than any other chief of protocol in the history of the United States.

Queen Elizabeth II behind a cluster of microphones at a lectern set up for Mr. Bush’s height at the White House in 1991.CreditDoug Mills/Associated Press

Most memorable was the affair of the talking hat. In May 1991, Queen Elizabeth II, at the start of an official visit, stepped up to a lectern on the White House lawn to deliver a few remarks. Unfortunately, the lectern was sized for the president, who was eight inches taller than the queen, and her face was hidden behind a cluster of microphones.

“You literally could not see her face as she spoke; just the hat bobbing up and down,” Barbara Bush wrote in “Barbara Bush: A Memoir” (1994). A Reuters reporter described the queen as looking like “a giant talking mushroom.”

When one newspaper ran a photograph of the event with the caption “The Talking Hat,” the slip-up entered the annals of diplomacy.

His boss, although furious at the time, ultimately overlooked the episode. In a statement to the newspaper Greenwich Time for its obituary of Mr. Reed, Mr. Bush called him “the quiet mastermind who literally helped set the stage for the diplomatic progress we made during a historic period of global change.” He called him “the ideal chief of protocol — perhaps the finest in modern history.”

Joseph Verner Reed Jr. was born on Dec. 17, 1937, in Manhattan and grew up in Greenwich. His father, Joseph Sr., spent much of the family’s oil and mining riches backing Broadway shows, a less than successful pursuit that he recounted in a 1935 memoir, “The Curtain Falls.” He also helped found the American Shakespeare Festival in Stratford, Conn. His mother, the former Permelia Pryor, devoted herself to charitable causes.

After attending Deerfield Academy, Mr. Reed earned a bachelor’s degree from Yale in 1961. While at Yale, he married Marie Byers, known as Mimi. She died in 2015. He is survived by their two daughters, Serena Reed Kusserow and Electra Reed; a brother, Nathaniel; and four grandchildren.

After Yale, Mr. Reed served two years as private secretary to Eugene R. Black, the president of the World Bank. In 1963, he became the chief of staff to David Rockefeller, the chairman of Chase Manhattan Bank, often acting as advance man on Mr. Rockefeller’s foreign trips. In 1979, Mr. Rockefeller handed him the unenviable task of bringing the deposed shah of Iran to the United States. He left Chase in 1981 to become ambassador to Morocco.

As chief of protocol, Mr. Reed helped organize the ceremonies surrounding the summit meeting between Mr. Bush and Mikhail S. Gorbachev in June 1990, as well as numerous meetings between Mr. Bush and Prime Minister John Major of Britain, President François Mitterrand of France and other world leaders.

“Protocol is what keeps the architecture of international diplomacy in place,” Mr. Reed told People magazine in 1990. “Without it, you’d have chaos. It isn’t a question of which fork to use — that plays a minor role. What is very important is the framework in which the host government and the visiting government conduct state business.”

Mr. Reed never quite outlived the Talking Hat imbroglio. In 1993, representing the United Nations, he dined on the royal yacht Britannia in Cyprus and once again encountered the queen.

She remembered him. In an interview with The Greenwich Sentinel last year, he recalled that she suddenly pointed to him and said, “You should have the Talking Hat on your tombstone.”

A version of this article appears in print on , on Page A21 of the New York edition with the headline: Joseph Verner Reed Jr., 78, Protocol Chief Who Presided Over Colorful Gaffe, Dies. Order Reprints | Today’s Paper | Subscribe